Steering mechanism for motor vehicles



March 6, 1945. w M, B AGDEN 2,371,022

STEERING MECHANISM FOR MOTOR VEHICLES Filed Nov. 16, 1942 5 Sheets-Sheetl FIG. I.

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ATTORA/E Y5 March 6, 1945. w. M. BLAGDEN STEERING MECHANISM FOR MOTOR VEHICLES 5 Sheets-Sheet 2 Filed Nov. 16, 1942 2 v 1 0w mw mm 3 i E Q mw mm mw Q mm om J mm Q Q m 9 3 INVENTOR ATTORNEYS March 6, 1945 w, BLAGDEQ 2,371,022

STEERING MECHANISM FOR MOTOR VEHICLES Filed NOV. 16, 1942 5 Sheets-Sheet 3,

5 y "Io 2 3 I/VV TOR 7 l7 Q fh A TTORNEYS March 6, 1945. w. M, BLAGDEN STEERING MECHANISM FOR MOTOR VEHICLES 5 Sheets-Sheet 4' Filed Nov. 16, 1942 FIGS.

INVENTOR W fpmm AT TOR/VEY March 6, 1945. w. M. BLAGDEN 2,371,022

STEERING MECHANISM FOR MOTOR VEHICLES Filed NOV. l6, 1942 5 Sheets-Sheet 5 FIGJA. Q '25FIG.7B.

29 FIGBA.

INVENTOR M wmfpm ATTORNEY 5 Patented Mar. 6, 1945 STEERING IVIECHAN'ISM FOR MOTO VEHICLES William Martin Blagden, Egham, England Application November 16, 1942, Serial No. 465,762

In Great Britain June 5, 1941 7 Claims. (Cl. 180-50) This invention relates to steering mechanism for motor vehicles operative on all four wheels, and has for its object to provide improved means for facilitating the steering of such vehicles when travelling in either direction, wherein the operation of the steering wheel or like device, when the vehicle is travelling in a forward direction, will first steer the front road wheels, and

upon their reaching the position of full or maximum look, further turning movement of the steering wheel in the same directionwill then steer the rear road wheels onto full lock whereby the diameter of the circle is reduced within which the vehicle may be turned, and wherein means are also provided which are adapted to be operated by the actuating mechanism of the reverse gearing to cause the front road wheels to be locked, and the rear road wheels to be placed under the control of the steering wheel, so that turning movement of the steering wheel will first steer the rear road wheels to full or maximum look when a further turning movement of the steering wheel in the same direction will then steer the front wheels onto full or maximum lock.

The present invention is characterized by the provision and use of a differential or rotary mechanism incorporated in the steering mechanism and coupled to the rotating shaft driven by the steering wheel, and also adapted to be coupled to the rotating shafts driving the front and rear road wheel steering gears respectively to effect the progressive steering of the front and rear road wheels, or the rear and front road wheels, according to the direction in which the vehicle is geared to travel.

The invention also consists in means for controlling or looking the rotary or differential mechanism in the steering mechanismforcausing either the front or the rear road wheels to be locked, and at the same time causing either the front or the rear wheels to be placed under the control of the steering wheel or like device when the vehicle is travelling in either direction.

The invention will be more completely understood from the following detailed description, given in conjunction with the accompanying drawings, in which:

Figures 1 and 2 are side and plan views respectively of a four wheeled vehicle embodying a steering mechanism constructed in accordance with the invention, the vehicle itself being in' skeleton form, only those parts having been shown which are essential for illustrating the method of connecting up the steering mechanism itself.

Figure 3 shows an enlarged longitudinal sectional view of one form of differential steering mechanism embodying the features of the invention.

Figure 4 showsa sectional plan view taken on line 4-4 of, Figure 3.

Figure 5 shows a transverse section taken on line 5-5 of Figure 3, showing the mechanism in v the position assumed when the front wheels are locked in straight alignment and the rear wheels adapted to be steered.

Figure 6 is a similar view to that of Figure 5, but showing the mechanism in the position assumed when the steering of the rear wheels has been turned to full lock, and the front wheels have been unlocked and are about to be made progressively steerable.

Figures 7, 7A and 7B are respectively a plan view and a side and a front elevation of one of the escapement pinions.

Figures 8 and 8A are respectively an end and a side elevation of the notched wheel adapted to be mounted on the slidable escapement shaft.

Figures 9 and 10 show respectively sectional views of the escapement wheel and pinion taken on lines 9--9 and Ill-l0 respectively'of Figure 3. Figures 11 and 12 show respectively sectional views of the escapement wheel and pinion taken on lines ll--ll and l2-I2 respectively of Figure 3.

According to one practical invention the differential or rotary mechanism incorporated in the steering mechanism comprises a, differential of the bevel gear type in which the differential pin of star piece I carrying the pinions 2 engaging with the differential gears 3 and 4 is connected tothe steering column 5 through a shaft 5 on which is fixed a bevel pinion 1 engaging with a bevel'pinion 8 mounted on the lower end of the said steering column 5 adapted to be driven by the steering wheel 9, the

said gearing being conveniently mounted on suitable bearings within a built-up casing 10. The

differential gear 3 meshing with one side of the central pinions 2 on the star piece I of the differential gearing is fixed to a shaft ll connected to a conventional steering gear box l2 arranged to operate the steering of the front wheels I3 through the usual levers and drag links M and track rod I5, while the differential gear 4 meshing with the other side of the central pinions 2 on the star piece I of the differential gearing is mounted on a tubular shaft I6 on which is formed or fixeda bevel pinion l1 engaging with a bevel pinion IS on a shaft l9 connected, as seen in Figure 2, by a shaft 20 through a crown pinion gear box 2| and shaft 22 and conventional steering gear box l2a arranged to operate the steering of the rear wheels 23 through the usual levers and drag links Ma and track rod l5a.

Means are provided 'as hereinafter described to effect the locking of the differential gear 3 coupled to the shaft ll arranged to drive the front steering gear 12 while the differential gear embodiment of this 4 coupled to the shaft I6 arranged to drive the rear steering gear I2a is free to be driven by the pinions 2 of. the differential mountedionthetstanpiece I which is; connected to andfarrangedito be turned or driven by the steering wheel 9, said means being also adapted to obversely effect the;

locking of the differential gear 4 coupled to the shaft I6 arranged to drive the rears'teering' gearthe said escapement wheel 4a,, but clear of en- I2a while the differential gear 3 coupled to the shaft I I arranged to drive the front \steerinagear is free to operate in the manner as before described.

When the gear 3 of the diiferentialwhich--is-= coupled to the shaft I I driving the front steering;-

gear I2 is turned sufficient to turn the front road Wheels l 3 to full or maximum lockin eitherd-i-' rection, the aforesaid locking means. are adapted to automaticallydock "said differential gear 3 and at the: same -time unlock 'the differential gear coupled to the shaft l 9 driving thea'ear steering:

box: I260 so that a -con-tinued turning movement' of the steering wheel 9 in the-same direction will steer-the rear IOadWhElS-23 onto' fullor maximum lock:

The aforesaid locking means are-interconnect ed with the lever arrangedto change the power transmission gears -from-=forward toreverse I drive' so thatwhen the reverse drive is engaged for driving thevehicle-in the reverse direction, the said locking means 'are operated-so as to reverse their action. -When the action-of the-'said'lo'ck ing means is" reversed and-the differential gear coupled to' the-sh'aft'--I Q driVing'the rear steering gear box I2a-isturned by an amount sufficient tosteerthe rearroad-wheels onto full or maximum lock'ineither direction,'-'said lockingmeans lock said gear 'and at-th'e same time unlock the gearcoupled"tothe-shaft 'II *driving the front steering gear box" I 2? so that continued turning of'the steering --Wh'eel '9in-the same direction steers the front road wheels I3 onto full lock-s In'1on-e convenient arrangementjthe aforesaid lockingme'ans; as seeniinFigures '3 to 12; comprise -escapementwheels 3a and da incorporated res-pectively-"with-the differential gears 3 andfi disposed oneach side of'gthecentral'pinions 2 and-arranged todrive the front and rear steering gearboxes l 2 ,and I an, the said \escapement wheels ta and iar each-having formed in the periphery-thereof "oneno'tch, 24;" 24a, adapted ,to be engaged respectively' by either, one of two. sets of 'teeth 25; 25a on escapement pinions 26;* 26a mountedon a shaft?! 'wh'ichis slidably and rockably carried in the casing I Oj'of the diiferential-box, and 'on said shaft"?! isalso k'eyedja wheel 28; as seen in-Figures 45,16, 8and 8A; in which-is formed a series of fth'ree notches 29" adapted'to be engaged by aspring controlled pawl 30" which is pivotally mounted'inthe differential jcasing Ilkwhereby the aforesaid 'escapement' shaftZ'I afterh'aving imparted thereto a slight gagement therewith, thus permitting turning movement of said.:.di1ferential gear wheel 4 to effect the turning or steering of the rear road wheels with which said differential gear wheel is operatively connected.

Onwthe v star piece I which carries the bevel pinions 2 of the differential is incorporated an armcSI ='carrying :a::roller 32 arranged to engage witlr-an arm fl on the '-pawl 30 adapted for engagement with"; the: notched 1' wheel 28 1 on: the escapement shaft 21;? the said 1 arm 33 having formed-' thereon a 1 suitably shaped cam: face 34 I so\:arrangedth'at when the star piece I of the difierenti'al; which is connected to and operated by--: thesteeringcolumn 5; has been turnedthrough one half of a -complete revolution, as

seen -in Figure 6; which said movement operating through thedifferential gear Wheel '4" is arranged" to turn, the rear road wheels to full lock, and in which operationthe-differential gear is turned through nearly a complete revolution so that the -notch 24a in its :escapement wheel 4a is-brought to'a -positionready for-engagement with one of the teeth 25a on the escapement pinion 26a, the

said arm-33 will be movedso as to'liftthe-pawr 30.sfrom"engagement with the notched wheel 28 l on'wthe escapementshaft 21, to unlock -and'permit of apart turnin move'mentof said shaft 27: A-continued turning'movement of the steering wheel '9 in'the same'direction-will cause the differential-"gear wheel'3 to be unlocked and-simultaneouslyeffect -the locking-- of the differential gear wh'eel 4-which--is connected to and arranged tooperate-thesteering' ofthe rear road-Wheels 23eand-willialso effect the locking of the escape ment shaft 2 'li'which is caused to be slightly tionzwillthen-impart a p turned by'. the. reaction :of the differential gear wheel'twhich brings zone 0f the outer'notches ZQdm-thawheel; 28 inztheshaftfl under-thernose:

of ,the-slocking zpawl- .3 0 which is thenfree. to move 1 ytthespring 35; as fixedto the starpiece into, engagement: therewith :b

l of: :the differential gea-r5-Wi1l-;ha.ve -moved clear of :enea ementqwithythezcamzface:34 onithejarni 3 3.o fp the :lockihgmawl 30.1; Furtherturning move? merits-of the; steering wheelv9.-in* the; same ,direc-- regressive steering move-- ment. to the front road vwheels -;I 3.;

The, ;aforesaid-rs1idab1eI escapment. shaft 27 :of; 1 the locking mechanismpis garranged randgadapted to Joe "operated :by; theieve'r employed -for -chang rocking or turning movement can be lockedjin'j either one :of "three posit ions to (prevent rotation j The aforesaid escapernentjpinions 26 land 2661, which are keyed to the slidable' and 'rockable escapement shaft 21," andarrangedflto effect the of the differential gear wheel 3, to e'if'ect locking 75 ing; the power transmission ,gears .fromforward ,1

to reverse-e drive. mer t, as seen in control lever :36 pivotally carried on a bracket 31 In one convenient arrangee mounted .on the longitudinal'side member :of the. chassis frame, .saidlever;- 3 6- being connected to. v; the. transmission gear unit 38' by racking levers; andli'nkage .39 operating. througha rockingshaft d0,v transversely mounted ,ibetweenr the sidememe bers of. the chassis} frame.

shaft 30 is also connected bylinkage 4 I 1andnavbellecranklever. 42 to the .e Slide abletesoapement 'shaftZlZ' I 4 I "is spring loaddjto permit. ;off the, control ;1ever 36'being moved to a when the steering is not in a straight-ahead po- The, said rocking suitable levers and,

The aforesaid linkage.-

cutate' the reverse gears When the control ,lever 36 is operated to change the transmission gears to either forward or reverse, and if the steering is not in a straight ahead position, movement will take place in the spring loaded linkage 4| giving a pre-load to the steering differential escapement shaft 21. When the steering passes through the straight ahead position in which the teeth 25 on the escapement pinions 26 and 26a and the notches 24 and 24a on the escapement wheels 3a and 4a assume a position in alignment, this pre-load will impart sliding movement to the escapement shaft 21 and thus cause the steering to change over.

When the escapement shaft 21 is slid say to the left, that is from the position on the right as previously described and illustrated in Figure 3, the single tooth 25 on the escapement pinion 2611 on the left will slide into engagement with the single notch 24a in the escapement wheel 4a of the diiferential gear wheel 4 connected to the rear steering box 12a thus preventing the turning of same, that is the rear steering will be locked, and simultaneously the single tooth 25 on the escapement pinion 26 on the right will slide out of engagement with the single notch 24 in the escapement wheel 3a of the differential gear wheel 3 connected to the front steering box l2, and the two teeth 25a on said escapement pinion 28 will assume a position over the periphery of the aforesaid escapement wheel, but clear of engagement therewith. The forward progressive steering of the vehicle can then be effected in the manner as previously described with reference to the rear steering.

The action of the locking means can thus be so conditioned by actuation of the control lever 36 so that by operation of the steering wheel 9 or like device the successive steering of the front and rear road wheels, or the rear and front road wheels, is selectively carried out according to the direction in which the vehicle is geared to travel.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. Steering mechanism for a motor vehicle having front and rear wheels for steering it, comprising steering gear boxes connected to the front and rear wheels respectively for steering them, differential mechanism embodying a pair of difierential gears, means connecting said gears respectively to said gear boxes, a differential member carrying pinions meshing with said gears, a steering Wheel connected to said diiferential member for operating it, devices cooperating with the respective differential gears and controlling their rotation, and means controlling said devices to permit rotation of said gears successively and thereby effect progressive steering of the front and then the rear wheels and to lock the front wheels and effect steering ofthe rear wheels.

2. Steering mechanism according to claim 1, wherein said controlling means is adjustable to prevent rotation of said gear which is connected to the front wheels to lock said wheels from steering movement and to permit rotation of the other of said gears to effect steering of the rear wheels.

3. Steering mechanism according to claim 1, including reverse driving control means for the vehicle, and wherein said controlling means has means for adjusting it by said reverse driving control means of the vehicle to lock one of said gears to lock the front wheels from steering movement and permit operation of the other of said gears to effect steering by the rear Wheels.

4. Steering mechanism according to claim 1, wherein said diiierential member comprises a star piece carrying said pinions, and said difier ential gears engage opposite sides of said pinions, and said controlling means causes said devices to lock one of said difierential gears and simultaneously unlock the other of said gears to permit successive steering of the front and rear Wheels.

5. Steering mechanism according to claim 1, wherein said devices comprise notched escapement Wheels on the respective differential gears, and said controlling means comprises escapement pinions having sets of teeth engageable with said escapement wheels, a slidable shaft on which said escapement pinions are mounted, said escapement pinions being movable by said slidable shaft to bring one of said pinions into looking relation with one differential gear while the other pinion is movable into a position to free the other differential gear for rotation to operate. the road wheels to which it is connected, and means operative, when said road wheels have been steered to full lock, to lock the differential gear by which they were operated, while the other differential gear is freed to steer the other road wheels by a continued turning movement of the steering wheel.

6. Steering mechanism for a motor vehicle having front and rear wheels for steering it, comprising a steeringwheel controlled operating member, differential gears connected respectively to the front and rear wheels for steering them and operable differentially bysaid operating member, means for locking one of the differential gears while the other is simultaneously unlocked to permit progressive steering of the front and rear road wheels, including a notched escapement wheel on each of said differential gears, escapement pinions each having two sets of teeth and engageable by one of their sets of teeth in the notches of the respective escapement wheels for controlling rotation of said differential gears, a rotatable shaft on which said escapement pinions are mounted and slidable to engage one or the other of said pinions with its respective escapement wheel, a notched wheel fixed on said shaft, a spring-controlled pivoted bell-crank lever engageablev with said notched wheel for controlling rotation of said shaft, and an arm actuated by said operating member and controlling said lever.

'7. Steering mechanism according to claim 6, including a reverse gear lever for the vehicle, and a spring-loaded linkage between said reverse gear lever and said slidabl and rotatable shaft for pro-loading said linkage to effect sliding movement of said shaft and escapement pinions.

WILLIAM MARTIN BLAGDEN. 

